U.S. Bank will provide the funds for Sungevity's leasing program, Kennedy said in an interview. The bank is also the financial arm for the leasing programs offered by SunRun and Solar City. Sungevity, though, says it will one-up the other two competitors with more competitive terms.

First, the term of the lease is only ten years, versus 15 to 18 years. After the ten-year period is up, consumers can extend their leases under the same terms or upgrade their solar systems.

Second, Sungevity will guarantee that customers save money. "More than 60 percent of customers will be cash-flow positive or neutral from day one," he said. For the remaining 40 percent, Sungevity will provide cash rebates ranging up to $800 for a limited time. Sungevity will also give customers payments between the time from when the customer signs the contract and the solar panels begin to generate energy. If an installation is delayed two months, for instance, and the solar panels would have saved $60 a month, Sungevity cuts a check for $120.

Business, he added, is accelerating. Sungevity will install 330 kilowatts this month. The company currently focuses on the California market. Sungevity came to prominence with an application that allows installers to conduct solar estimates over the internet. Online estimates eliminate the need for the in-home visit and can cut the cost of a solar system by 5 percent or more. Sungevity will handle the financing and sales process, but it outsources installation.

Meanwhile, in the past few weeks, the long predicted shift of big box retailers and home builders into the growing market for energy efficiency services and renewable energy has begun.

Select Lowe's outlets have begun to offer retrofit services in conjunction with Recurve. Lowe's performs the retrofits, but uses Recurve's software to plan and conduct the audit.

Late last year, Lowe's also began to sell the all-in-one solar panels from Akeena Solar and followed it up with a deal in mid-March in which Akeena will serve as an installer for Lowe's. Meanwhile, 92 Home Depot outlets in northern California will begin to sell solar panels and installation services in conjunction with Solar City starting April 2.